density

I must admit that I am not a big fan of the commercial side of Valentine’s day but I have no problem with the idea of telling someone you love just how much they mean to you. When I get to couple the sentiment with some science experimenting then my heart really does skip a beat. Check out these cool valentine science experiments that would make some pretty unique (and educational) gifts for the someone special in your life.

Say it with flowers

Who doesn’t love flowers on Valentine’s Day? With a little bit of science you can add an extra twist to this staple gift. Try these CHROMATOGRAPHY flowers…

Here’s what you’ll need:

Some paper (we used regular white A4 paper here)

A selection of water soluble coloured markers

A pencil

A ruler

A paperclip

A glass or beaker

A jug of water

Some wire or pipe cleaners

What to do:

Fold your paper in half down the long side and then open it out again.

Using your ruler and a pencil, draw a line either side of the crease, the line should be about 2 cm from the crease on each side.

Choose the colours you would like to use and place large dots of each colour along these lines, leaving about 1 – 2 cm between each dot. Alternate the colours in whatever way you wish.

Once you have that done it is time to fold your paper. You need to fold along the shorter side, start at one end and fold the edge of the paper in about 2 cm. Turn over the paper and fold back another 2 cm. Turn over the paper and keep going like this until you reach the other side of the paper.

Keeping the paper folded, fold it in half and secure with a paperclip.

Trim the tops of the folded paper on each side. I used a serrated scissors but you could just cut into a pointy shape or round off the ends, whatever you prefer.

Pour about 1 cm of water into your glass (or beaker) and place the folded paper into the glass, as in the photo below. You want the end of the paper to sit into the water below the dots of markers, you don’t want the water level to reach the dots though.

Now you just need to wait a while. You should see the water creeping up the paper, spreading out the marker ink as it moves upwards. Once the water reaches the top of the paper you can remove it from the beaker and place it somewhere warm to dry.

Replace the paper clip with a strip of wire or a pipe cleaner, and twist it to close. This will be the stem of the flower.

Once dry it is time to open out the paper, into a flower shape, and see what a colourful CHROMATOGRAPHY flower you have made. You can try different types of paper, blotting paper works really well.

The science bit:

This experiment used a scientific technique called CHROMATOGRAPHY to separating different chemicals; in this case the chemicals are the inks in coloured markers. As the water creeps up the paper (by a process called CAPILLARY ACTION) it dissolves the different inks that make up the colour. These inks separate out as the water moves upwards and you get lovely streaks of colours through the paper.

If you prefer real flowers to artificial ones you can still use a bit of science to add some extra colour; Here are two of our favourites (click the images below to find out how to make these beautiful coloured flowers while learning all about TRANSPIRATION!).

Make a multicoloured Rose (click the image to find out more).

Or try making a rainbow bunch of flowers, click the image above to go to the blog post.

2. You make my heart spin

I’ll admit these do take an extra bit of time and effort but they are really worth it and give a nice WOW factor. Your Valentine will be amazed with a gift like this… left wondering just how you did it. This experiment requires ADULT SUPERVISION!

Here is what you’ll need:

Some copper wire

a pliers

a strong scissors or wire cutter

A battery (AA work just fine), I used a D battery here

A neodymium magnet (these are strong, rare earth magnets, often found in electrical appliances but can be purchased in many specialised shops)

Some items to decorate (optional)

And this is what you do:

You can start by decorating your battery with love hearts or similar stationary if you wish.

Place the neodymium magnet on the base (minus side) of the battery, it will ‘stick’ to the metal.

Now for the tricky bit, you need to make a connection from the positive end of the battery, to the other side (the magnets in this case) to complete an electrical circuit. You can see from the photo and video below that I shaped one end of the copper wire into a heart shape with a little ‘stalk’ to sit on the top of the battery. I then wrapped the remaining wire around the battery and finally, I wrapped the end of the wire around the neodymium magnet (in this case I used two small neodymium magnets, one on top of the other). You will know if the circuit is complete as the battery and copper wire will heat slightly. However in order to get the wire to start to move you need to ensure that the wire is balanced correctly and is not wrapped too tightly around the battery or magnet. It will take a bit of patience and ‘tweaking’ to get this right, but, hopefully you will be rewarded by a lovely spinning heart 🙂

Want to know how it works?

Congratulations, you have just created a HOMOPOLAR MOTOR and, by combining an elctrical current and a magnetic field, working in specific directions, you have generated a force called LORENTZ force, that makes the copper wire move.

To put it as simply as possible, the copper wire connect to the positive and negative ends of the battery, completing a circuit and creating an electrical current that runs through the wire. The neodymium magnet generated a permanent magnetic field. In this set up the electrical current is perpendicular to the magnetic field and this generated teh Lorentz Force which acts on the copper wire, making it move!

NOTE: This experiment requires adult supervision! An electrical current can generate heat and you need to be careful that nothing gets too hot.

3. Gooey with love

Slime may not be the first thing that comes to mind when thinking of a Valentine’s day gift but this one is the prettiest slime I’ve ever made, and it has love hearts and sparkles in it, so what’s not to love. Plus… a few minutes playing with this stuff is time well spent, it is actually a great stress busting exercise, try it and see!

What you will need:

A bottle of clear glue

A jug of water

Bowl and something to stir with

A cup or small plastic cup or a second bowl

Borax powder

glitter and mini hearts (or any decoration of your choice)

Here is what you do:

Pour a small amount of clear glue into your bowl (we used a 10 ml at a guess). Add the little of the love hearts and glitter, just a small sprinkle of each is fine.

Give all that a good mix and then leave to the side while you make up the borax solution

In the cup (or jug) make up your borax solution; you want to dissolve 1/2 teaspoon of borax powder in a cup measure of warm water (about 240 ml); Stir until fully dissolved.

Still the glue constantly and add a very small amount of borax solution. Keep stirring all the time. As soon as the glue is no longer sticky you can pick it up in your hands and start kneading and molding it, for a few minutes.

I will admit that I had a lot of trouble coming up with a good recipe here. I am used to working with white glue (PVA) which makes great slime. The clear glue can get very rubbery slime which breaks easily. So the trick is to use small amounts and add as little borax solution as possible. Also, once the slime forms at all, take it into your hands and knead it.

You can even roll it into a ball and see how bouncy it is…

I know that borax is not easy to buy in Ireland at the moment so I will test out some alternatives and hopefully have a post next week with some borax-powder-free slime recipes!

The science bit:

Congratulation… you have just made a polymer!! In simple terms a polymer is a substance made up of lots of molecules arranged in long chains. If you imagine that the glue is like cooked spaghetti, it slides and slips around the place quite easily. When we add the borax to the glue it causes some of the molecules in the glue to stick together making the glue more rubbery and less liquid! Imagine if you took those strands of spaghetti and tied them together in places, the strands would not be able to slip and slide around nearly as much! The borax and glue mixture is just like your knotted spaghetti!

What you do:

First add a few drop of red food colouring to the water until you are happy with the colour.

Add about half a teaspoon of glitter and half a teaspoon of miniature hearts to the water and mix well.

Using the funnel, pour the coloured water into the bottle, filling it to about a third full.

Fill the rest of the bottle with oil (using the funnel again) and replace the lid. You will notice that the oil and water remain as two separate layers.

Hold the bottle on its side and tilt it slowly back and forwards, you will see the water moves like a coloured wave, it gives a lovely effect.

If you want to turn this into a Valentine’s lava lamp just stand the bottle back up again, open the lid and pop in half an antacid tablet (like Alkaseltzer) NOTE: these tablets are not for eating and this part must be supervised by an adult.

Pop the lid back on (don’t seal it fully though as gas will build up in the bottle) and watch your lovely lava lamp.

When it stops you can pop in another piece of Alkaseltzer and watch all over again.

The science bit:

This is a good experiment to explain density. The oil is less dense than the water so it will sit on top of the water, creating two separate layers. The layer of oil keeps the water contained within the bottom half of the water and makes the movement of the water look like waves where the two liquids meet.

When we add the Alkaseltzer tablets to the bottle we get a chemical reaction. The tablets contain an acid and a base (or alkali) in powder form. When the tablet sinks down to the water layer the tablet dissolves and the acid and base get to mix together, forming carbon dioxide gas. The gas forms bubbles, and is lighter than the water and oil so the bubbles float to the top of the bottle where they burst, leaving just a drop of water, which is more dense than the oil so it falls back down. This cycle gives a lovely lava lamp effect of bubbles and blobs rising and falling through the oil layer. We are loving this one in our house at the moment. The glitter and love hearts add a really lovely touch to the whole thing.

So there you have it… five of our favourite Valentine experiments, I’m sure you’ll agree, as well as being educational, these would make great gifts for someone you love! We hope you get as much fun out of making these as we did and remember to let us know how you get on!

HAPPY VALENTINE’S DAY!!!

*****

If you’d like to know a little about the Science of Love, check out this post!

Using the funnel fill the plastic bottle about one third full with water

Add a few drops of food colouring to colour the water blue

Using the funnel again fill the bottle with the oil (you will notice that the water and oil will quickly settle into two separate layers)

Close the lid tightly on the bottle and turn the bottle on its side

The water layer will be on the bottom of the bottle

If you rock the bottle from side to side you can create a wave like motion of the water, looking just like a little ocean in a bottle; see what kind of waves you can make!

Ocean in a bottle

How does it work…

This is a good experiment to explain density. The oil is less dense than the water so it will sit on top of the water, creating two separate layers. The layer of oil keeps the water contained within the bottom half of the water and makes the movement of the water look like waves where the two liquids meet.

I have discussed density in more detail in this previous post as well as sharing lots more density experiments.

If you get bored of your ocean in a bottle, why not stand it upright again and add some Alka Seltzer tablets to instantly turn it into a lava lamp!

What is Density?

Density is the mass of an object per unit volume. A bit of a mouthful but this is how I explained it to my own children today….

…imagine you have a pebble and a marshmallow of the same size and shape… which one do you think is heavier?

My three year old got this straight away… “the pebble of course Mum” (with a “silly question” look that I am use to at this stage).

The Fun Friday Science Team!

So if they are the same size (volume) then why does one weigh so much more than the other? If you remember that everything is made up of molecules… the heavier object simply has more molecules packed more tightly together (a greater mass); the molecules in the lighter object (in this case the marshmallow) are much more loosely packed together (a smaller mass)!

The pebble is said to have a greater density than the marshmallow.

A bit of History:

A Greek scientist called Archimedes (250 BC) is credited with discovering the concept of density. The story goes that Archimedes was given the task of determining if the newly minted King’s gold coins were genuine (or if they had been mixed with silver). Archimedes was pondering this idea while lowering himself into the bath. When he noticed how his body displaced a volume of water he realised he had cracked it! If he compared a coin of pure gold with the newly minted ones he could check if they displaced the same amount of water i.e. that their densities were the same. Turns out they were not and the King was beings duped!

They say that Archimedes was so excited when he realised the solution that he jumped out of the bath and ran all the way home naked shouting “Eureka, Eureka”…. (“I found it, I found it” in Greek).

Here are some experiments on density that you can try at home…

The children and I spent the afternoon trying out these cool experiments that are easy to do at home. Hope you get to try some too!

1. Make a density rainbow

You will need:A clear glass, golden syrup or honey, maple syrup, milk, washing up liquid, water, food colouring, cooking oil or baby oil, a clear alcohol (we used isopropanol but you could use methylated spirits or vodka – with adult supervision!), funnels, a dropper or a spoon.

What to do:Place some water in a glass and add a few drops of food colouring and mix. Place some alcohol in another glass and add a few drops of a different food colouring. Mix.

Carefully add each layer in the following order….

golden syrup

maple syrup

milk

washing up liquid

coloured water

baby oil (or cooking oil)

coloured alcohol

Try to add each layer carefully down the side of the glass, using a spoon, a dropper or a funnel (as below). Make sure each liquid makes a complete layer that fully covers the layer underneath. If the layers mix a little, allow to settle before adding the next layer.

Add each layer carefully down the side of the glass

Two junior scientists admiring their work!

We think it looks lovely!

What is happening:

We added the most dense material first (the golden syrup) and then the next dense and so on. So each layer is a little lighter or less dense than the previous one and therefore floats on it.

You can of course add other things are leave some of these layers out!

2. Lava lamp in a glass

You will need: a clear glass, sunflower/vegetable oil, water, food colouring, some effervescent tablets such as AlkaSeltzer.

What to do: Place water in the glass to about one third full. Add a few drops of food colouring to the water and mix. Gently pour the oil down the side of the glass filling the glass to almost the top. If the oil and water mix a little don’t worry, just wait a while until the two layers separate out with the oil sitting on top of the water. Break the tablet into pieces and add one or two pieces to the glass…. I will let Caer explain it to you (with a little prompting from her brother)!

What is happening:

When the AlkaSeltzer tablet reaches the water layer it starts to dissolve and fizz, releasing a gas called carbon dioxide. This gas forms in small bubbles surrounded by water, they start to rise to the top of the glass because the gas is lighter (less dense) than the water and oil. The bubbles pass all the way through the oil layer to the top of the glass where the bubble eventually bursts, releasing the carbon dioxide gas. Once the gas is gone the bubble is just water, which is heavier (more dense) than the oil so it starts to drop down again. The process continues until all the carbon dioxide has escaped to the top. Adding more AlkaSeltzer starts it all off again!

3. Fireworks in a glass

You will need: A glass, water, food colouring and sunflower (or vegetable) oil

What to do: Fill the glass with water to about two thirds full. Carefully pour a layer of oil on top of the water to fill the glass. Add drops of food colouring to the top of the oil layer and watch as they slowly drop down and enter the water layer. They streak through it like some mini fireworks!

Add the drops of food colouring to the top of the oil…

…and wait for the fireworks display to begin!

What is happening:

Food colouring and oil do not mix so the drops will fall until they meet the water layer. Food colouring dissolves in water, the colour diffuses out into the water as the drops fall to the bottom of the glass, giving a lovely fireworks type display!

Hope you enjoyed this week’s Fun Friday as much as we did. If you have any comments, questions or suggestions please leave a comment below, I always love the chat and feedback!